1. Field of the Invention
This invention is directed toward an off-road vehicle for transporting goods.
The invention is more particularly directed toward a simple off-road vehicle for loading and transporting elongated articles, particularly trees.
2. Description of the Prior Art
Vehicles for transporting trees are well known. The most commonly used vehicles, known as skidders, have means at their rear end for grabbing and lifting a bundle of trees by their butt end. The skidders then drag the bundle of trees from one location to another for further processing. The known skidders normally have four wheels, each of which can be independently mounted on the chassis of the skidder. The known skidder is thus quite stable even when travelling over rough generally level ground and is very manoeuverable. In addition, the known skidders are quite simple in construction and easy to operate thus making them inexpensive and reliable.
However, the known skidders have disadvantages. In a conventional choke skidder, the loading and unloading of the trees from the skidder takes a relatively long time, compared to the time required to transport the trees. The loading and unloading time can comprise 80 to 85% of the total loading, transport and unloading time. A conventional grapple skidder can load and unload much quicker than a choker skidder. However, the conventional grapple skidder has very poor load distribution because the load is carried well behind the rear axle of the skidder. As a result, the grapple skidder is quite unstable, particularly when working on slopes where it is liable to jack-knife. To provide more stability, the payload is often reduced. The known skidders usually drag the trees by their butt ends. However in dragging the trees, the trees become dirty and the dirt can cause damage or excessive wear on equipment used in subsequent tree processing operations. In handling trees, particularly smaller trees, by their butt ends, one or more trees are frequently dropped when dragging a bundle of the trees from one location to another. Extra time must be spent in recovering these dropped trees. At the collection location, the transported trees are piled together for further processing. However the known skidders cannot easily travel on high piles of trees to add their loads of trees to the pile so that the height of the piles is limited and more storage space is needed. When the skidders do travel on lower piles of trees, they can only move forward on the pile starting from the top end while transporting a tree bundle. Thus the height of the pile is further limited to that height which allows the skidders to safely move off the butt end of the pile. If a higher pile of trees is desired, the front blade of the skidder is used to bulldoze and push the unloaded trees into a higher pile. However this adds another step to the tree processing operation which increases the cost since the added step is time consuming. In addition, this added step is hard on the skidder leading to more frequent maintenance. With the known skidders it is also difficult to bunch the trees at the felling site into a load, since the trees normally can only be pulled into position. Often there is not enough room at the felling site to allow the skidder room to manoeuvre to pull the felled trees into a suitable load, and other means must be employed to bunch the trees.
Vehicles for transporting goods, such as trees, over rough ground employ various types of wheel mountings. Smaller, four wheel vehicles have each wheel simply, rigidly connected to the chassis. This however results in a rough ride, unequal wheel loading, and limited use in rough terrain. Other four wheel vehicles have each wheel movably, independently mounted on the chassis. This arrangement provides a smoother ride and more equal wheel loading permitting use in rough terrain. However independent, movable wheel mountings are expensive. Vehicles with six or more wheels often have two or more wheels on each side paired and mounted on the ends of a walking or pivoted beam to provide a bogie mounting. The bogie mounting of each pair of wheels, on each side of the vehicle, makes the vehicle suited for travel over rough ground in a simple manner. However bogie mountings are only used on vehicles with six or more wheels in order to provide the necessary stability.